To do what?
Discussion
Because to do most tasks the answer is any old well built one running a good linux distro.
If audio / video production the answer may be different, if gaming then different again.
What's the answer for audio/video laptops?
Also what do people think of miniPCs? For the same task. #asknostr
Usually a Mac Pro, whether you use Mac OS or Linux depends on what software you want to run, simpler stuff without all the plugins you can probably get away with Linux.
It's unfortunate but most of the audio / video industry codes for Mac, would really like to see that change.
You could give https://ubuntustudio.org/ a go on one.